CSS:

#overlay wdg-menu-kavftig ul li:nth-child(1) span {
  font-size: 30px;
  padding:  5px 10px 7px 10px;
  background-color: #fff;
  cursor: default;
  line-height: unset;
}

#overlay wdg-menu-kavftig ul li{
  border: 0;
  margin: 5px 0;
}

#overlay wdg-menu-kavftig ul li span:hover{
background-color: rgba(0, 0, 0, 1) !important;
color: #fff;
}

#overlay wdg-menu-kavftig a:hover{
background-color: rgba(0, 0, 0, 0) !important;
}

#overlay wdg-menu-kavftig button{
  background-color: #fff;
  margin: 5px 0 0 20px !important;
  border-radius: 0px !important;
  width: auto;
}

.menu {
  box-shadow: unset;
  margin-top:15px !important;
  background-color: rgba(0, 0, 0, 0);
}

#overlay wdg-menu-kavftig ul li:nth-child(n+3)  span{
  background-color: #fff;
  padding: 0 10px 0 10px ;
  margin-left: 30px;
  width: unset;
  line-height: unset;
}

#overlay wdg-menu-kavftig ul li:nth-child(2)  span{
  background-color: #fff;
  padding: 0 10px 0 10px ;
  width: unset;
  cursor: default;
  line-height: unset;
}

#overlay wdg-menu-kavftig ul li:nth-child(n+8)  span{
  background-color: #000;
  color: #fff;
  padding: 0 10px 0 10px ;
  width: unset;
}

Preview: